As an oral pathology resident with a PhD in immunology, Dr. Kramer is interested in autoimmune diseases with oral manifestations, and has chosen to study Sjogren's syndrome (SS). While her long-range goals are to direct her own laboratory, teach, and participate in patient care within an academic institution, her immediate goals are to acquire the knowledge and skills necessary to conduct autoimmune research independently. She will achieve these goals under the mentorship of Dr. Rothstein, an accomplished clinician scientist, at the Feinstein Institute for Medical Research (FIMR). Accordingly, the FIMR places a strong emphasis on translational research, and will provide a rich collaborative environment in which to conduct her proposed project. Moreover, she will participate in courses and seminars, and will also attend conferences in accordance with her career development plan. She is well poised to accomplish her goals, as she has successfully completed a challenging DDS/PhD program, and is now working with an experienced mentor who has considerable expertise in B cell biology. Dr. Kramer's proposal focuses on SS, a rare autoimmune disease that primarily affects the glands that produce tears and saliva. The primary form of SS (pSS) affects the salivary and lacrimal glands predominantly, while the secondary form (sSS) occurs in conjunction with other autoimmune connective tissue disorders. SS patients demonstrate increased tooth decay, have difficulty speaking and chewing, and have many systemic complications as well. Many types of immune cells are essential in the development and progression of autoimmunity, and this proposal will focus B cells in particular. While B cells are clearly important in SS, their contribution to disease initiation and progression is not well understood. The first aim of this proposal seeks to gain a fundamental understanding of SS etiology. In this aim, we will examine the anatomic location and the specific B cells subsets responsible for autoantibody production in SS, as well as immunoglobulin gene usage and fine antibody specificity. In specific aims 2 and 3, we will seek to identify innovative therapeutic targets in SS. Specifically; we will determine whether inhibition of a specific mediator that drives B cell recruitment, termed CXCL13, will ameliorate the pathology observed in SS. We will neutralize CXCL13 in an SS mouse model and evaluate disease severity. Moreover, we will extend these studies to pSS patients to determine whether serum and/or salivary CXCL13 levels correlate with disease severity. Finally, we will examine the CXCL13 receptor in SS. We will determine whether subsets expressing high levels of this receptor produce autoantibodies preferentially, and whether expression of this receptor is influenced by inflammatory mediators that are present in SS. Results from these studies will likely result in the identification of fundamental disease mechanisms that are poorly defined in SS to date, and innovative therapeutic targets for the treatment of this disease that may result in significant improvements in the both the oral and systemic health of patients afflicted with SS.